For baby-boomers, there is both good news and bad news about the cognitive health of the aging brain.
Brain researcher Gary Small from UCLA conveys the bad news first: "Reaction time is slower," he says. "It takes us longer to learn new information. Sometimes it takes us longer to retrieve information, so we have that tip-of-the-tongue phenomenon — where you almost have that word or that thought. That's typical of the middle-age brain."
As we age, our ability to multi-task diminishes. "We're quick, but we're sloppy when we're in middle-age. We make more errors when we're in middle age," says Small. The Older, But Wiser, Brain
But Small has found that it's not all bad news. He points to a continued improvement in complex reasoning skills as we enter middle age. Small suggests that this increase may be due to a process in the brain called "myelination." Myelin is the insulation wrapped around brain cells that increases their conductivity — the speed with which information travels from brain cell to brain cell. And the myelination doesn't reach its peak until middle age. By this point, says Small, "the neuro-circuits fire more rapidly, as if you're going from dial-up to DSL." Complex reasoning skills improve, and we're able to anticipate problems and reason things out better than when we were young.
And, Small adds, there's another area of improvement as we age: empathy — the ability to understand the emotional point of view of another. Empathy increases as we age. 'Your Brain On Google'
One of the great discoveries from recent neuroscience research is that the human brain is always changing, from moment to moment and throughout life. It continues to develop, and even continues to grow new brain cells.
"An old myth in neuroscience," says Small, "is that once a brain cell dies off you can't replace it." But many studies have now shown, he adds, that there is, in fact, brain cell growth throughout life. So, he says, the brain can continue to learn throughout the middle age years and beyond.
In a recent study that Small refers to as "your brain on Google," healthy, middle-aged volunteers, all novices on the computer, were taught how to do a Google search. They were told then to practice doing online searches for an hour a day, for seven days. After the week's practice, the volunteers came back into Small's lab and had their brains scanned while doing a Google search.
The scans revealed significant increases in brain activity in the areas that control memory and decision-making.
"The area of the brain that showed the increases was the frontal lobe, the thinking brain, especially in areas that control decision making and working memory," Small says. One interpretation of his findings, he says, is that with practice, a middle-age brain can very quickly alter its neuron-circuitry, can strengthen the neuron circuits that control short-term memory and decision making. Physical Fitness Helps Brain, Too
Research by neuroscientist Art Kramer, from the University of Illinois, highlights the plasticity — the ability to grow and change — of the aging brain. In his studies on physical exercise, Kramer has found that memory can improve with treadmill workouts.
"Over a six-month to one-year period," Kramer says, "three days a week, working up to an hour a day, people improved in various aspects of both short-term and long-term memory."
After treadmill training, the "aging couch potatoes," as Kramer calls them, were given brain scans. Those who'd trained had larger hippocampi, the brain area key for memory. Other brain regions too — central for decision-making, planning and multi-tasking — were also larger in the treadmill exercisers. "There are a number of regions," says Kramer, "that on MRI scans tend to show not just stability but increases as a function of exercise in middle-age and older brains."
Such research studies underscore that both physical exercise and cognitive brain training contribute to brain health. And these two scientists not only talk the talk, they also, quite literally, walk the walk. Kramer, 56, goes to the gym four or five days a week, getting aerobic exercise on a stationary bike and strength training by lifting weights. Small, 58, does a New York Times crossword and numbers puzzle every morning, as well as a series of toning and stretching exercises and at least 20 minutes of aerobic exercise each
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Nowadays, some scientists say, you can exercise your brain the way you exercise your body.
If you sleep more, eat less and get plenty of exercise — using your body and your brain — says Richard Restak, you can improve your intelligence over the years and help stave off the dementia that comes with old age.
Restak, a psychiatrist in Washington, D.C., is the author of the just-published Think Smart: A Neuroscientist's Prescription for Improving Your Brain's Performance. Research shows, he says, that the brain responds to stretching and challenging exercises in every stage of life.
An older person "can still take up a language, you can learn to play bridge," he says, "and that establishes connections between neurons, and the synaptic density begins to increase."
In other words, as we get older, we can still get smarter.
The key, Restak says, is to exercise the three different types of memory: long-term memory, sensory memory and working memory. Making Memories — Stronger
"Long-term memory is just everything we know about history, things about our life, important dates, important things that happened, all the things that separate one person from another," Restak explains. "You could call it the treasure-trove of information that you have. So that's long-term memory, and we're forming it all the time."
He suggests an exercise to increase the strength of long-term memory: Choose a year in your past and associate it with what you were doing — where you were in school or where you were working. Then expand your recollections into other events in the world at large — sporting contests, political activities, major catastrophes and cultural happenings.
"It's called a reminiscent exercise," he says. "It can be used at any time in life."
There is controversy surrounding the ability to improve memory and intelligence through exercises. Torkel Klingberg, a Swedish brain researcher and author of The Overflowing Brain, says that "certain cognitive functions, such as attention, working memory and possibly reasoning … can be affected by training." But he is less certain that exercises will strengthen long-term memory.
Restak says that we are constantly adding to our long-term memory, and learning to associate images or emotions with those memories will increase the chances of retrieval. Your Brain On Peanut Butter
Sensory memory is the recall associated with the senses, such as touch, smell and hearing. Restak says, "Sensory memory is something you don't hear too much about, yet it's the most important part of laying down a memory: Paying attention to what's going on."
For instance, we don't remember a person's name, he says, "because we weren't listening when we met them. Why don't we remember certain facts? It's because we weren't really there."
To stimulate the sensory memory, Restak suggests testing your powers of olfaction. He writes that "eighty-five percent of the U.S. population can identify the following seven odors: baby powder, chocolate, cinnamon, coffee, mothballs, peanut butter and soap."
So go into the kitchen, close your eyes and ask someone to hand you each of those items — opened so you can sniff them — one by one. Or use spices. Or other familiar odors to connect your nose to your memory. Try to identify as many as you can. Then try again and see if you can improve your fragrance memory. The Working Memory Workout
Of all forms of memory, the working memory is the most vital to our everyday lives. "That's the area of being able to keep in mind several things at once," Restak says.
To exercise working memory, Restak suggests a few radical ideas, including video games for adults that reinforce focus and dexterity skills.
And a self-quiz: Name the U.S. presidents, going backward from Barack Obama to John F. Kennedy. Then, arrange them in chronological order starting with Kennedy, assigning each his proper party affiliation (so, Kennedy — Democrat; Johnson — Democrat; etc.). Next, list them alphabetically. That ability to perform more than one function at a time, Restak says, stretches the working memory.
In the end, Restak believes we should think of the brain's growth over the years as a series of marathons. He credits Canadian neurologist Kenneth Rockwood with the metaphor. In Think Smart, Rockwood says, "As our brains age, we must prepare them to resist injury — equip them with good education, train them thoughtfully with challenging regimens, support them with nurturing environments and be prepared to refresh them from time to time."
Looking at the old noodle that way, Restak says, encourages an active brain — one that will keep working and stay fit through the years.
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Can't Remember Faces? Blame Your Genes
by Jon Hamiltonwww.NPR.org
February 22, 2010
People who struggle to remember faces can blame their parents.
That's because the ability to remember a face is inherited, according to a paper in the Proceedings of the National Academy of Sciences. Researchers also found that people who are good at remembering faces are not necessarily good at other memory tasks.
Taken together, these results strongly support the idea that face recognition ability comes from a dedicated circuit, or set of circuits, in the brain.
Facial Recognition Test
Courtesy of Jeremy Wilmer
An illustration from the face-recognition study. Nearly 300 pairs of twins were asked to memorize six faces. They were then shown three more faces and asked to identify the one face they had seen before. Identical Twins, Nearly Identical Ability To Remember
The paper, which comes from an international team, included two different studies.
The first looked at nearly 300 pairs of twins. Some were identical, meaning they share all their genes; others were nonidentical twins, who share only half their genes.
All the twins took a test that involved memorizing six faces. Then, participants were shown three more faces and were asked to identify the one face in this group they had seen before.
Web Resources
Study Findings In PNASTest Your Own Face Recognition Ability
The face recognition ability of pairs of nonidentical twins often differed quite a bit, says Jeremy Wilmer, the study's lead author and a psychologist at Wellesley College in Massachusetts.
But that wasn't the case with pairs of identical twins, whose performance was "extraordinarily similar," Wilmer says.
These results offer strong evidence that "face recognition ability is a highly familial trait," Wilmer says. Using A Special Part Of The Brain
The second study used a Web site to test the ability of several thousand people to remember faces, word pairs and abstract art images. The study found no link between face recognition ability and scores on the other tasks.
All of this supports the idea that there is a part of the brain that specializes in processing faces, says Nancy Kanwisher, a brain scientist at MIT.
The most likely candidate is the "fusiform face area," which is located "just behind and underneath, and a bit from your right ear," Kanwisher says.
She says it makes sense that our genes would include special code for such an area, because faces are so important to humans and some other primates.
Faces tell us whether we know a person, what mood they're in, how old they are, and whether they are looking at us or something else, Kanwisher says. "All this rich visual information you can get from a brief glimpse of a face."
Face recognition appears to be so basic, she says, that it is actually hard-wired into the brain. Similar Findings In Monkeys
Japanese researchers provided strong evidence of this in an experiment with monkeys a couple of years ago, Kanwisher says.
The researchers spent years raising monkeys who never saw a face — human or monkey. The animals were separated from other monkeys, and their human caretakers wore masks.
Even so, when the monkeys were tested, they had "adult-like face discrimination abilities," Kanwisher says, adding that this is probably because the ability to recognize faces is carried in our genes and present from birth.
The finding in monkeys is consistent with experiments on human babies just a few days old, Wilmer says.
When a baby is presented with representations of things like a circle or square and a face, Wilmer says, "The baby will spend a lot of time looking at the face relative to the other
Decades of research suggest that sleep is a time when the brain processes things it has learned, and this latest study found we can influence which memories the brain strengthens during sleep.
You may not be able to learn a foreign language in your sleep, but you can strengthen certain memories, according to a study in the journal Science.
The study, led by researchers at Northwestern University, found that hearing certain sounds during a nap helped people remember information associated with those sounds once they woke up.
"They were a little bit better, a little more accurate," says John Rudoy, a graduate student at Northwestern and the study's lead author.
The study builds on decades of research suggesting that sleep is a time when the brain processes things it has learned, Rudoy says.
"When you take a nap or have a full night's sleep after learning something, you're actually better at it the morning after," he says. Memorizing Images
Rudoy and a team of researchers thought it might be possible to influence which memories the brain strengthened during sleep. So they recruited a dozen volunteers and taught them to play a special game on the computer.
The game involved studying 50 images, one at a time, accompanied by appropriate sound cues. The image of a cat was accompanied by a meow, while the image of a breaking wine glass featured the sound of breaking glass.
Each image was assigned to a specific location on the screen. The cat might always appear in the lower left, for example, while a train might always show up in the top right.
After some practice, the volunteers took a test that showed they had become pretty good at remembering the location associated with each image.
Then they took a nap. Sleep Sounds
Once brain monitors showed that a person was deeply asleep, the scientists began to play the sound cues for some, but not all, of the images.
After the volunteers woke up, they took the test again. And they were better at remembering the correct location for the images associated with sounds they heard in their sleep, Rudoy says.
The volunteers didn't remember which sounds they'd heard while asleep, Rudoy says. But apparently, some part of their brain could.
"It got in there somehow and seemed to strengthen the particular memories that were associated with those sound cues," Rudoy says. Better Performance
The effect was pretty modest. And the result doesn't suggest the brain can learn something completely new during sleep, Rudoy says.
Even so, it's still a pretty startling finding, says James McGaugh, a neurobiology professor and memory expert at the University of California, Irvine.
"What it suggests is that there is a way to provide additional information during sleep that will strengthen memories that had been previously formed," he says Consolidation
In the past few decades, much of the research on sleep and memory has focused on a process called consolidation, in which some of the things we learn gradually become integrated into the networks in our brain.
Studies have suggested that a lot of consolidation goes on during REM sleep, which is when we dream. But the new study looked at deep sleep, about which much less is known.
Also, the new study found that hearing sound cues while awake did not have the same effect as hearing them while asleep.
McGaugh says he finds that puzzling, and says the results do not fit neatly into what's known about memory consolidation during sleep.
But he adds that the findings are "provocative and interesting," and bound to lead to more studies on ways to influence memories while we sleep.
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Most high schools begin their day around 7:30 a.m., which leaves many teenagers nodding off in the morning. In fact, at least 20 percent of high school students fall asleep in class on a typical day. The problem: Teenagers need a lot of sleep — about nine hours each night, experts say. And most of them aren't getting enough.
To help sleepy teens, some school districts have tried delaying the opening of the high school day. Educational researcher Kyla Wahlstrom, from the University of Minnesota, has been following districts that changed their start times, tracking the effect on schools and students. The Minneapolis school district, for example, changed its start time from 7:20 to 8:40 a.m., giving its 12,000 high schoolers an extra hour and twenty minutes each morning. Wahlstrom says the students have benefited from the change.
"Students reported less depression when there was a later starting time," she says. "And teachers reported that students were more alert and ready for learning. Parents reported that their children were easier to live with because their emotions were more regulated."
Additionally, Wahlstrom found a decrease in the number of students who were dropping out of school or moving from school to school.
According to the National Sleep Foundation, more than 80 school districts around the country have now made the change to start their high schools later. These districts range from large, urban school districts, such as Minneapolis and Denver, to suburban districts, such as Jessamine County in central Kentucky.
In Jessamine County, detailed discussions about starting their high schools later took place over a year and a half. All the stakeholders — parents, teachers, coaches, kids, transportation directors — were included in the conversation. Eventually, a plan emerged: The district decided to flip the elementary school start time with the high school start time. Research shows that young children aren't sleepy in the early morning, unlike the typical teenager.
So in 2003, Jessamine County's high schools started 50 minutes later. School District Supervisor, Lu Young, says the change has had a big impact at the high schools.
"We found that our students were more on time and in better attendance first period than they had been in the past," she says.
For many school districts, a major obstacle in changing their start times is the cost and scheduling of buses. Some districts, however, have juggled their bus schedules without any additional expense. The West Des Moines School District in Iowa, for instance, was able to actually reduce the number of buses needed by changing the start times of all three tiers of their school system.
Kay Rosene, director of community relations at the West Des Moines School District, says the switch gave the district a windfall of about $700,000 annually. Rosene adds that the potential savings was very appealing to the West Des Moines school community.
"It meant that other potential cuts in programming or curriculum offerings would not occur," she says.
Another challenge some school districts grapple with is the concern that after-school sports schedules would be affected by starting the high schools later. That was a central worry at the Mahtomedi School District in Minnesota. But a solution was found, says Superintendent Mark Wolak.
The high school students agreed to shorten the number of minutes they take to get from one class to another — a delay called "passing time." The result was that the high schoolers could start school later but end their school day at about the same time, without disrupting the athletic schedule. Since 2005, first bell for the students has been 35 minutes later. Wolak says parents were surveyed — and they overwhelmingly endorsed the decision, 5 to 1.
Wolak adds that teachers especially wanted a change because, "They were concerned about student attendance and student readiness to learn that first period of the day."
"One of the anecdotal findings was that we noticed better attendance and less student sleeping in class that first hour," Wolak says.
Research on the sleep needs of adolescents and their ability to pay attention and learn in the early morning hours supports Wolak's observations.
When adolescence hit Frances Jensen's sons, she often found herself wondering, like all parents of teenagers, "What were you thinking?"
"It's a resounding mantra of parents and teachers," says Jensen, who's a pediatric neurologist at Children's Hospital in Boston.
Like when son number one, Andrew, turned 16, dyed his hair black with red stripes and went off to school wearing studded leather and platform shoes. And his grades went south.
"I watched my child morph into another being, and yet I knew deep down inside it was the same Andrew," Jensen says. Suddenly her own children seemed like an alien species.
Jensen is a Harvard expert on epilepsy, not adolescent brain development. As she coped with her boys' sour moods and their exasperating assumption that somebody else will pick up their dirty clothes, she decided to investigate what neuroscientists are discovering about teenagers' brains that makes them behave that way.
Jensen's older son Andrew, now a physics major at Wesleyan, is the reason his mother first started studying the teenage brain. She wanted to find out what was causing his maddening teenage behavior.
Jensen's older son Andrew, now a physics major at Wesleyan, is the reason his mother first started studying the teenage brain. She wanted to find out what was causing his maddening teenage behavior. Teenage Brains Are Different
She learned that that it's not so much what teens are thinking — it's how.
Jensen says scientists used to think human brain development was pretty complete by age 10. Or as she puts it, that "a teenage brain is just an adult brain with fewer miles on it."
But it's not. To begin with, she says, a crucial part of the brain — the frontal lobes — are not fully connected. Really.
"It's the part of the brain that says: 'Is this a good idea? What is the consequence of this action?' " Jensen says. "It's not that they don't have a frontal lobe. And they can use it. But they're going to access it more slowly."
That's because the nerve cells that connect teenagers' frontal lobes with the rest of their brains are sluggish. Teenagers don't have as much of the fatty coating called myelin, or "white matter," that adults have in this area.
Think of it as insulation on an electrical wire. Nerves need myelin for nerve signals to flow freely. Spotty or thin myelin leads to inefficient communication between one part of the brain and another.
Jensen's younger son Will is now a Harvard student. He says he learned a lot about his teenage brain from his mother.
Jensen's younger son Will is now a Harvard student. He says he learned a lot about his teenage brain from his mother. A Partially Connected Frontal Lobe
Jensen thinks this explains what was going on inside the brain of her younger son, Will, when he turned 16. Like Andrew, he'd been a good student, a straight arrow, with good grades and high SAT scores. But one morning on the way to school, he turned left in front of an oncoming vehicle. He and the other driver were OK, but there was serious damage to the car.
"It was, uh, totaled," Will says. "Down and out. And it was about 10 minutes before morning assembly. So most of the school passed by my wrecked car with me standing next to it."
"And lo and behold," his mother adds, "who was the other driver? It was a 21-year-old — also probably not with a completely connected frontal lobe." Recent studies show that neural insulation isn't complete until the mid-20s.
This also may explain why teenagers often seem so maddeningly self-centered. "You think of them as these surly, rude, selfish people," Jensen says. "Well, actually, that's the developmental stage they're at. They aren't yet at that place where they're thinking about — or capable, necessarily, of thinking about the effects of their behavior on other people. That requires insight."
And insight requires — that's right — a fully connected frontal lobe.
Teen Brains Are Not Fully Connected
The brain's "white matter" enables nerve signals to flow freely between different parts of the brain. In teenagers, the part that governs judgment is the last to be fully connected.
The brain's
Source: Nature Neuroscience 2003
Credit: Elizabeth Sowell More Vulnerable To Addiction
But that's not the only big difference in teenagers' brains. Nature made the brains of children and adolescents excitable. Their brain chemistry is tuned to be responsive to everything in their environment. After all, that's what makes kids learn so easily.
But this can work in ways that are not so good. Take alcohol, for example. Or nicotine, cannabis, cocaine, ecstasy ...
"Addiction has been shown to be essentially a form of 'learning,' " Jensen says. After all, if the brain is wired to form new connections in response to the environment, and potent psychoactive drugs suddenly enter that environment, those substances are "tapping into a much more robust habit-forming ability that adolescents have, compared to adults."
So studies have shown that a teenager who smokes pot will still show cognitive deficits days later. An adult who smokes the same dose will return to cognitive baseline much faster.
This bit of knowledge came in handy in Jensen's own household.
"Most parents, they'll say, 'Don't drink, don't do drugs,'" says Will, son number two. "And I'm the type of kid who'd say 'why?' "
When Will asked why, his mom could give him chapter and verse on drugs and teen brains. So they would know, she says, "that if I smoke pot tonight and I have an exam in two days' time, I'm going to do worse. It's a fact."
There were other advantages to having a neuroscientist mom, Will says. Like when he was tempted to pull an all-nighter.
"She would say, 'read it tonight and then go to sleep,'" he says. "And what she explained to me is that it will take [what you've been reading] from your short-term memory and while you sleep you will consolidate it. And actually you will know it better in the morning than right before you went to sleep."
It worked every time, he says.
It also worked for Andrew, the former Goth. He's now a senior at Wesleyan University, majoring in physics.
"I think she's great! I would not be where I am without her in my life!" Andrew says of his mom.
For any parent who has survived teenagers, there are no sweeter words.
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Willpower And The 'Slacker' Brain
by Robert Krulwichwww.NPR.org
January 26, 2010
This time, you say to yourself, this time I will do 50 chin-ups every day or skip dessert or call my mother every Friday. It's time to do those things that I know, I really, really know I should do.
And then you don't.
According to British psychologist Richard Wiseman, 88 percent of all resolutions end in failure. Those are his findings from a 2007 University of Hertfordshire study of more than 3,000 people.
How come so many attempts at willpower lose both their will and their power?
In our Radiolab excerpt on Morning Edition, with my co-host, Jad Abumrad, we propose an answer ...
Jonah Lehrer, one of our regular reporters (he writes all the time about the brain), told Jad and me about an experiment involving the prefrontal cortex, located just behind the forehead. It's the brain area largely responsible for willpower. This hunk of brain tissue, he says, has greatly expanded over the last few hundred-thousand years, but "it probably hasn't expanded enough." The reason our willpower is so often weak, he suggests, is because this bit of brain lacks a certain (how shall we put this?) ... muscularity. The Experiment
In his book How We Decide, and in a recent Wall Street Journal article, Jonah writes about an experiment by Stanford University professor Baba Shiv, who collected several dozen undergraduates and divided them into two groups.
In the WSJ article, Jonah writes:
"One group was given a two-digit number to remember, while the second group was given a seven-digit number. Then they were told to walk down the hall, where they were presented with two different snack options: a slice of chocolate cake or a bowl of fruit salad."
Cake and fruit
iStockphoto.com
And then he writes:
"Here's where the results get weird. The students with seven digits to remember were nearly twice as likely to choose the cake as students given two digits. The reason, according to Professor Shiv, is that those extra numbers took up valuable space in the brain — they were a "cognitive load" — making it that much harder to resist a decadent dessert. In other words, willpower is so weak, and the prefrontal cortex is so overtaxed, that all it takes is five extra bits of information before the brain starts to give in to temptation."
It turns out, Jonah explains, that the part of our brain that is most reasonable, rational and do-the-right-thing is easily toppled by the pull of raw sensual appetite, the lure of sweet. Knowing something is the right thing to do takes work — brain work — and our brains aren't always up to that. The experiment, after all, tells us brains can't even hold more than seven numbers at a time. Add five extra digits, and good sense tiptoes out of your head, and in comes the cake. "This helps explain why, after a long day at the office, we're more likely to indulge in a pint of ice cream, or eat one too many slices of leftover pizza," Lehrer writes.
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Damage to the brain of a teenage drinker, side view
EnlargeCourtesy of Susan Tapert/Tim McQueeny, UCSD
The red specks highlight where the integrity of the brain's white matter is significantly less in the teens who binge drink, compared to those who do not.
For teenagers, the effects of a drunken night out may linger long after the hangover wears off.
A recent study led by neuroscientist Susan Tapert of the University of California, San Diego compared the brain scans of teens who drink heavily with the scans of teens who don't.
Tapert's team found damaged nerve tissue in the brains of the teens who drank. The researchers believe this damage negatively affects attention span in boys, and girls' ability to comprehend and interpret visual information.
"First of all, the adolescent brain is still undergoing several maturational processes that render it more vulnerable to some of the effects of substances," Tapert says.
In other words, key areas of the brain are still under construction during the adolescent years, and are more sensitive to the toxic effects of drugs and alcohol.
Damage to the brain of a teenage drinker, top view
Courtesy of Susan Tapert/Tim McQueeny, UCSD
Damage to the brain of a teenage drinker, top view Thought, Memory Functions Affected
For the study, published last month in the journal Psychology of Addictive Behaviors, Tapert looked at 12- to 14-year-olds before they used any alcohol or drugs. Over time, some of the kids started to drink, a few rather heavily — consuming four or five drinks per occasion, two or three times a month — classic binge drinking behavior in teens.
Comparing the young people who drank heavily with those who remained non-drinkers, Tapert's team found that the binge drinkers did worse on thinking and memory tests. There was also a distinct gender difference.
"For girls who had been engaging in heavy drinking during adolescence, it looks like they're performing more poorly on tests of spatial functioning, which links to mathematics, engineering kinds of functions," Tapert says.
And the boys?
"For boys who engaged in binge drinking during adolescence, we see poor performance on tests of attention — so being able to focus on something that might be somewhat boring, for a sustained period of time," Tapert says. "The magnitude of the difference is 10 percent. I like to think of it as the difference between an A and a B." Teenage Tendency To Experiment To Blame
Pediatrician and brain researcher Ron Dahl from the University of Pittsburgh notes that adolescents seem to have a higher tolerance for the negative immediate effects of binge drinking, such as feeling ill and nauseated.
"Which makes it easier to consume higher amounts and enjoy some of the positive aspects," Dahl says. "But, of course, that also creates a liability for the spiral of addiction and binge use of these substances."
He adds that there is a unique feature of the teenage brain that drives much behavior during adolescence: The teen brain is primed and ready for intense, all-consuming learning.
"Becoming passionate about a particular activity, a particular sport, passionate about literature or changing the world or a particular religion" is a normal, predictable part of being a teenager, he says.
"But those same tendencies to explore and try new things and try on new identities may also increase the likelihood of starting on negative pathways," he adds. Damaged Brain Tissue
Tapert wanted to find out in what way binge drinking affects a teen's developing brain. So using brain imaging, she focused on the white matter, or nerve tissue, of the brain.
"White matter is very important for the relay of information between brain cells; and we know that it is continuing to develop during adolescence," Tapert says.
So Tapert imaged the brains of two groups of high school students: binge drinkers and a matched group of teens with no history of binge drinking. She reports in her recent study a marked difference in the white matter of the binge drinkers.
"They appeared to have a number of little dings throughout their brains' white matter, indicating poor quality," Tapert says.
And poor quality of the brain's white matter indicates poor, inefficient communication between brain cells.
"These results were actually surprising to me because the binge drinking kids hadn't, in fact, engaged in a great deal of binge drinking. They were drinking on average once or twice a month, but when they did drink, it was to a relatively high quantity of at least four or five drinks an occasion," she says.
In another study, Tapert reported abnormal functioning in the hippocampus — a key area for memory formation — in teen binge drinkers. Reflecting their abnormal brain scans, the teen drinkers did more poorly on learning verbal material than their non-drinking counterparts.
What remains unknown, says Tapert, is if the cognitive downward slide in teenage binge drinkers is reversible.
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Hardwired For Doom: Brain, Mind And Fate
January 25, 2010 By Adam Frank www.NPR.org
"Get down from there!"
My 15-year-old son and I had just come out of the movie theater. After two hours of the usual explosions and mayhem (I can't really remember what movie we had seen) I made the mistake of telling him to wait outside while I chatted with a friend. Five minutes later I find him on the theater roof jumping from one large air conditioning unit to the other. "What are you crazy?" I yelled hoping to get him down, and us away, from there before the blue siren's arrived.
Well, yes. Of course he's crazy. He's 15. Ever since we made the mistake of watching District B13 my son has become a fan of Parkour, which is like freestyle skiing without skis or snow or mountains. Practitioners of Parkour (or its variant Free-running) believe that a good time equals climbing straight up the face of impossibly high walls or leaping from the roof of one 10 story building to another (even if there happens to be a city street in between them). It is a mix of gymnastics, rock climbing and insanity. It's beautiful, graceful and terrifying (if you are a parent). So of course my son loves it and yearns to be an adept. I am trying to guide him to something safer.
Which brings us to today's question. What is the balance between the hardwiring evolution has given us and the cultural programming we have given ourselves?
Brain researchers have found that thrill seeking like Parkour is, to some degree, programmed into the teenage brain. It's part of the need for intense learning. Eventually part of that learning will include internal dialogues like "Don't jump from that building. Its stupid and we will die." But until that kind maturation occurs teenagers need parents around to tell them "Don't jump from that building. Its stupid and you will die."
But we are more than just the hardwiring of our brains, aren't we? In many regards the brains we have now were set in place, genetically at least, some 50,000 years ago. But the difference in culturally constructed behavior between then (hunter-gathers living in small tribes) and now is so vast that we have clearly invented some powerful new behaviors. From the development of agriculture 9000 or so years ago to kingship based empires of the first few millennia BC to the crazy caffeine-fueled high-tech scramble we inhabit now, hasn't culture and not genetics driven our evolution?
This is a question of more than academic interest. One can imagine all kinds of genetically hardwired behavior that was really useful for small bands of social hominids a million years ago that present real problems for a now global species with nuclear weapons (among other toys). Evolutionary psychology combined with impressive advances in brain science is an exciting branch of research that lays bare the physical causes of some aspects of our behavior. But how much of that behavior is hardwired and how much lies in the "new" evolutionary domains of culture (created via the imagination)?
There is the world we are born into and the one we create. What are the boundaries between them and how much play do we have in pushing those boundaries around?
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The Aging Brain Is Less Quick, But More Shrewd
by Michelle Trudeau www.NPR.orgMarch 1, 2010
For baby-boomers, there is both good news and bad news about the cognitive health of the aging brain.
Brain researcher Gary Small from UCLA conveys the bad news first: "Reaction time is slower," he says. "It takes us longer to learn new information. Sometimes it takes us longer to retrieve information, so we have that tip-of-the-tongue phenomenon — where you almost have that word or that thought. That's typical of the middle-age brain."As we age, our ability to multi-task diminishes. "We're quick, but we're sloppy when we're in middle-age. We make more errors when we're in middle age," says Small.
The Older, But Wiser, Brain
But Small has found that it's not all bad news. He points to a continued improvement in complex reasoning skills as we enter middle age. Small suggests that this increase may be due to a process in the brain called "myelination." Myelin is the insulation wrapped around brain cells that increases their conductivity — the speed with which information travels from brain cell to brain cell. And the myelination doesn't reach its peak until middle age. By this point, says Small, "the neuro-circuits fire more rapidly, as if you're going from dial-up to DSL." Complex reasoning skills improve, and we're able to anticipate problems and reason things out better than when we were young.
And, Small adds, there's another area of improvement as we age: empathy — the ability to understand the emotional point of view of another. Empathy increases as we age.
'Your Brain On Google'
One of the great discoveries from recent neuroscience research is that the human brain is always changing, from moment to moment and throughout life. It continues to develop, and even continues to grow new brain cells.
"An old myth in neuroscience," says Small, "is that once a brain cell dies off you can't replace it." But many studies have now shown, he adds, that there is, in fact, brain cell growth throughout life. So, he says, the brain can continue to learn throughout the middle age years and beyond.
In a recent study that Small refers to as "your brain on Google," healthy, middle-aged volunteers, all novices on the computer, were taught how to do a Google search. They were told then to practice doing online searches for an hour a day, for seven days. After the week's practice, the volunteers came back into Small's lab and had their brains scanned while doing a Google search.
The scans revealed significant increases in brain activity in the areas that control memory and decision-making.
"The area of the brain that showed the increases was the frontal lobe, the thinking brain, especially in areas that control decision making and working memory," Small says. One interpretation of his findings, he says, is that with practice, a middle-age brain can very quickly alter its neuron-circuitry, can strengthen the neuron circuits that control short-term memory and decision making. Physical Fitness Helps Brain, Too
Research by neuroscientist Art Kramer, from the University of Illinois, highlights the plasticity — the ability to grow and change — of the aging brain. In his studies on physical exercise, Kramer has found that memory can improve with treadmill workouts.
"Over a six-month to one-year period," Kramer says, "three days a week, working up to an hour a day, people improved in various aspects of both short-term and long-term memory."
After treadmill training, the "aging couch potatoes," as Kramer calls them, were given brain scans. Those who'd trained had larger hippocampi, the brain area key for memory. Other brain regions too — central for decision-making, planning and multi-tasking — were also larger in the treadmill exercisers. "There are a number of regions," says Kramer, "that on MRI scans tend to show not just stability but increases as a function of exercise in middle-age and older brains."
Such research studies underscore that both physical exercise and cognitive brain training contribute to brain health. And these two scientists not only talk the talk, they also, quite literally, walk the walk. Kramer, 56, goes to the gym four or five days a week, getting aerobic exercise on a stationary bike and strength training by lifting weights. Small, 58, does a New York Times crossword and numbers puzzle every morning, as well as a series of toning and stretching exercises and at least 20 minutes of aerobic exercise each
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To Keep Your Brain Nimble As You Age, Stretch It
by Linton Weeks www.NPR.orgMay 12, 2009
Nowadays, some scientists say, you can exercise your brain the way you exercise your body.
If you sleep more, eat less and get plenty of exercise — using your body and your brain — says Richard Restak, you can improve your intelligence over the years and help stave off the dementia that comes with old age.Restak, a psychiatrist in Washington, D.C., is the author of the just-published Think Smart: A Neuroscientist's Prescription for Improving Your Brain's Performance. Research shows, he says, that the brain responds to stretching and challenging exercises in every stage of life.
An older person "can still take up a language, you can learn to play bridge," he says, "and that establishes connections between neurons, and the synaptic density begins to increase."
In other words, as we get older, we can still get smarter.
The key, Restak says, is to exercise the three different types of memory: long-term memory, sensory memory and working memory.
Making Memories — Stronger
"Long-term memory is just everything we know about history, things about our life, important dates, important things that happened, all the things that separate one person from another," Restak explains. "You could call it the treasure-trove of information that you have. So that's long-term memory, and we're forming it all the time."
He suggests an exercise to increase the strength of long-term memory: Choose a year in your past and associate it with what you were doing — where you were in school or where you were working. Then expand your recollections into other events in the world at large — sporting contests, political activities, major catastrophes and cultural happenings.
"It's called a reminiscent exercise," he says. "It can be used at any time in life."
There is controversy surrounding the ability to improve memory and intelligence through exercises. Torkel Klingberg, a Swedish brain researcher and author of The Overflowing Brain, says that "certain cognitive functions, such as attention, working memory and possibly reasoning … can be affected by training." But he is less certain that exercises will strengthen long-term memory.
Restak says that we are constantly adding to our long-term memory, and learning to associate images or emotions with those memories will increase the chances of retrieval.
Your Brain On Peanut Butter
Sensory memory is the recall associated with the senses, such as touch, smell and hearing. Restak says, "Sensory memory is something you don't hear too much about, yet it's the most important part of laying down a memory: Paying attention to what's going on."
For instance, we don't remember a person's name, he says, "because we weren't listening when we met them. Why don't we remember certain facts? It's because we weren't really there."
To stimulate the sensory memory, Restak suggests testing your powers of olfaction. He writes that "eighty-five percent of the U.S. population can identify the following seven odors: baby powder, chocolate, cinnamon, coffee, mothballs, peanut butter and soap."
So go into the kitchen, close your eyes and ask someone to hand you each of those items — opened so you can sniff them — one by one. Or use spices. Or other familiar odors to connect your nose to your memory. Try to identify as many as you can. Then try again and see if you can improve your fragrance memory.
The Working Memory Workout
Of all forms of memory, the working memory is the most vital to our everyday lives. "That's the area of being able to keep in mind several things at once," Restak says.
To exercise working memory, Restak suggests a few radical ideas, including video games for adults that reinforce focus and dexterity skills.
And a self-quiz: Name the U.S. presidents, going backward from Barack Obama to John F. Kennedy. Then, arrange them in chronological order starting with Kennedy, assigning each his proper party affiliation (so, Kennedy — Democrat; Johnson — Democrat; etc.). Next, list them alphabetically. That ability to perform more than one function at a time, Restak says, stretches the working memory.
In the end, Restak believes we should think of the brain's growth over the years as a series of marathons. He credits Canadian neurologist Kenneth Rockwood with the metaphor. In Think Smart, Rockwood says, "As our brains age, we must prepare them to resist injury — equip them with good education, train them thoughtfully with challenging regimens, support them with nurturing environments and be prepared to refresh them from time to time."
Looking at the old noodle that way, Restak says, encourages an active brain — one that will keep working and stay fit through the years.
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Can't Remember Faces? Blame Your Genes
by Jon Hamilton www.NPR.orgFebruary 22, 2010
People who struggle to remember faces can blame their parents.
That's because the ability to remember a face is inherited, according to a paper in the Proceedings of the National Academy of Sciences. Researchers also found that people who are good at remembering faces are not necessarily good at other memory tasks.
Taken together, these results strongly support the idea that face recognition ability comes from a dedicated circuit, or set of circuits, in the brain.
An illustration from the face-recognition study. Nearly 300 pairs of twins were asked to memorize six faces. They were then shown three more faces and asked to identify the one face they had seen before.
Identical Twins, Nearly Identical Ability To Remember
The paper, which comes from an international team, included two different studies.
The first looked at nearly 300 pairs of twins. Some were identical, meaning they share all their genes; others were nonidentical twins, who share only half their genes.
All the twins took a test that involved memorizing six faces. Then, participants were shown three more faces and were asked to identify the one face in this group they had seen before.
Web Resources
Study Findings In PNASTest Your Own Face Recognition AbilityThe face recognition ability of pairs of nonidentical twins often differed quite a bit, says Jeremy Wilmer, the study's lead author and a psychologist at Wellesley College in Massachusetts.
But that wasn't the case with pairs of identical twins, whose performance was "extraordinarily similar," Wilmer says.
These results offer strong evidence that "face recognition ability is a highly familial trait," Wilmer says.
Using A Special Part Of The Brain
The second study used a Web site to test the ability of several thousand people to remember faces, word pairs and abstract art images. The study found no link between face recognition ability and scores on the other tasks.
All of this supports the idea that there is a part of the brain that specializes in processing faces, says Nancy Kanwisher, a brain scientist at MIT.
The most likely candidate is the "fusiform face area," which is located "just behind and underneath, and a bit from your right ear," Kanwisher says.
She says it makes sense that our genes would include special code for such an area, because faces are so important to humans and some other primates.
Faces tell us whether we know a person, what mood they're in, how old they are, and whether they are looking at us or something else, Kanwisher says. "All this rich visual information you can get from a brief glimpse of a face."
Face recognition appears to be so basic, she says, that it is actually hard-wired into the brain.
Similar Findings In Monkeys
Japanese researchers provided strong evidence of this in an experiment with monkeys a couple of years ago, Kanwisher says.
The researchers spent years raising monkeys who never saw a face — human or monkey. The animals were separated from other monkeys, and their human caretakers wore masks.
Even so, when the monkeys were tested, they had "adult-like face discrimination abilities," Kanwisher says, adding that this is probably because the ability to recognize faces is carried in our genes and present from birth.
The finding in monkeys is consistent with experiments on human babies just a few days old, Wilmer says.
When a baby is presented with representations of things like a circle or square and a face, Wilmer says, "The baby will spend a lot of time looking at the face relative to the other
Sounds During Sleep May Help You Remember
by Jon Hamilton www.NPR.orgNovember 19, 2009
Decades of research suggest that sleep is a time when the brain processes things it has learned, and this latest study found we can influence which memories the brain strengthens during sleep.
You may not be able to learn a foreign language in your sleep, but you can strengthen certain memories, according to a study in the journal Science.The study, led by researchers at Northwestern University, found that hearing certain sounds during a nap helped people remember information associated with those sounds once they woke up.
"They were a little bit better, a little more accurate," says John Rudoy, a graduate student at Northwestern and the study's lead author.
The study builds on decades of research suggesting that sleep is a time when the brain processes things it has learned, Rudoy says.
"When you take a nap or have a full night's sleep after learning something, you're actually better at it the morning after," he says.
Memorizing Images
Rudoy and a team of researchers thought it might be possible to influence which memories the brain strengthened during sleep. So they recruited a dozen volunteers and taught them to play a special game on the computer.
The game involved studying 50 images, one at a time, accompanied by appropriate sound cues. The image of a cat was accompanied by a meow, while the image of a breaking wine glass featured the sound of breaking glass.
Each image was assigned to a specific location on the screen. The cat might always appear in the lower left, for example, while a train might always show up in the top right.
After some practice, the volunteers took a test that showed they had become pretty good at remembering the location associated with each image.
Then they took a nap.
Sleep Sounds
Once brain monitors showed that a person was deeply asleep, the scientists began to play the sound cues for some, but not all, of the images.
After the volunteers woke up, they took the test again. And they were better at remembering the correct location for the images associated with sounds they heard in their sleep, Rudoy says.
The volunteers didn't remember which sounds they'd heard while asleep, Rudoy says. But apparently, some part of their brain could.
"It got in there somehow and seemed to strengthen the particular memories that were associated with those sound cues," Rudoy says.
Better Performance
The effect was pretty modest. And the result doesn't suggest the brain can learn something completely new during sleep, Rudoy says.
Even so, it's still a pretty startling finding, says James McGaugh, a neurobiology professor and memory expert at the University of California, Irvine.
"What it suggests is that there is a way to provide additional information during sleep that will strengthen memories that had been previously formed," he says
Consolidation
In the past few decades, much of the research on sleep and memory has focused on a process called consolidation, in which some of the things we learn gradually become integrated into the networks in our brain.
Studies have suggested that a lot of consolidation goes on during REM sleep, which is when we dream. But the new study looked at deep sleep, about which much less is known.
Also, the new study found that hearing sound cues while awake did not have the same effect as hearing them while asleep.
McGaugh says he finds that puzzling, and says the results do not fit neatly into what's known about memory consolidation during sleep.
But he adds that the findings are "provocative and interesting," and bound to lead to more studies on ways to influence memories while we sleep.
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High Schools Starting Later to Help Sleepy Teens
by Michelle Trudeau www.NPR.orgJanuary 18, 2007
Most high schools begin their day around 7:30 a.m., which leaves many teenagers nodding off in the morning. In fact, at least 20 percent of high school students fall asleep in class on a typical day. The problem: Teenagers need a lot of sleep — about nine hours each night, experts say. And most of them aren't getting enough.
To help sleepy teens, some school districts have tried delaying the opening of the high school day. Educational researcher Kyla Wahlstrom, from the University of Minnesota, has been following districts that changed their start times, tracking the effect on schools and students. The Minneapolis school district, for example, changed its start time from 7:20 to 8:40 a.m., giving its 12,000 high schoolers an extra hour and twenty minutes each morning. Wahlstrom says the students have benefited from the change."Students reported less depression when there was a later starting time," she says. "And teachers reported that students were more alert and ready for learning. Parents reported that their children were easier to live with because their emotions were more regulated."
Additionally, Wahlstrom found a decrease in the number of students who were dropping out of school or moving from school to school.
According to the National Sleep Foundation, more than 80 school districts around the country have now made the change to start their high schools later. These districts range from large, urban school districts, such as Minneapolis and Denver, to suburban districts, such as Jessamine County in central Kentucky.
In Jessamine County, detailed discussions about starting their high schools later took place over a year and a half. All the stakeholders — parents, teachers, coaches, kids, transportation directors — were included in the conversation. Eventually, a plan emerged: The district decided to flip the elementary school start time with the high school start time. Research shows that young children aren't sleepy in the early morning, unlike the typical teenager.
So in 2003, Jessamine County's high schools started 50 minutes later. School District Supervisor, Lu Young, says the change has had a big impact at the high schools.
"We found that our students were more on time and in better attendance first period than they had been in the past," she says.
For many school districts, a major obstacle in changing their start times is the cost and scheduling of buses. Some districts, however, have juggled their bus schedules without any additional expense. The West Des Moines School District in Iowa, for instance, was able to actually reduce the number of buses needed by changing the start times of all three tiers of their school system.
Kay Rosene, director of community relations at the West Des Moines School District, says the switch gave the district a windfall of about $700,000 annually. Rosene adds that the potential savings was very appealing to the West Des Moines school community.
"It meant that other potential cuts in programming or curriculum offerings would not occur," she says.
Another challenge some school districts grapple with is the concern that after-school sports schedules would be affected by starting the high schools later. That was a central worry at the Mahtomedi School District in Minnesota. But a solution was found, says Superintendent Mark Wolak.
The high school students agreed to shorten the number of minutes they take to get from one class to another — a delay called "passing time." The result was that the high schoolers could start school later but end their school day at about the same time, without disrupting the athletic schedule. Since 2005, first bell for the students has been 35 minutes later. Wolak says parents were surveyed — and they overwhelmingly endorsed the decision, 5 to 1.
Wolak adds that teachers especially wanted a change because, "They were concerned about student attendance and student readiness to learn that first period of the day."
"One of the anecdotal findings was that we noticed better attendance and less student sleeping in class that first hour," Wolak says.
Research on the sleep needs of adolescents and their ability to pay attention and learn in the early morning hours supports Wolak's observations.
The Teen Brain: It's Just Not Grown Up Yet
March 1, 2010Richard Knox/NPR www.NPR.org
When adolescence hit Frances Jensen's sons, she often found herself wondering, like all parents of teenagers, "What were you thinking?""It's a resounding mantra of parents and teachers," says Jensen, who's a pediatric neurologist at Children's Hospital in Boston.
Like when son number one, Andrew, turned 16, dyed his hair black with red stripes and went off to school wearing studded leather and platform shoes. And his grades went south.
"I watched my child morph into another being, and yet I knew deep down inside it was the same Andrew," Jensen says. Suddenly her own children seemed like an alien species.
Jensen is a Harvard expert on epilepsy, not adolescent brain development. As she coped with her boys' sour moods and their exasperating assumption that somebody else will pick up their dirty clothes, she decided to investigate what neuroscientists are discovering about teenagers' brains that makes them behave that way.
Jensen's older son Andrew, now a physics major at Wesleyan, is the reason his mother first started studying the teenage brain. She wanted to find out what was causing his maddening teenage behavior.
Jensen's older son Andrew, now a physics major at Wesleyan, is the reason his mother first started studying the teenage brain. She wanted to find out what was causing his maddening teenage behavior.
Teenage Brains Are Different
She learned that that it's not so much what teens are thinking — it's how.
Jensen says scientists used to think human brain development was pretty complete by age 10. Or as she puts it, that "a teenage brain is just an adult brain with fewer miles on it."
But it's not. To begin with, she says, a crucial part of the brain — the frontal lobes — are not fully connected. Really.
"It's the part of the brain that says: 'Is this a good idea? What is the consequence of this action?' " Jensen says. "It's not that they don't have a frontal lobe. And they can use it. But they're going to access it more slowly."
That's because the nerve cells that connect teenagers' frontal lobes with the rest of their brains are sluggish. Teenagers don't have as much of the fatty coating called myelin, or "white matter," that adults have in this area.
Think of it as insulation on an electrical wire. Nerves need myelin for nerve signals to flow freely. Spotty or thin myelin leads to inefficient communication between one part of the brain and another.
Jensen's younger son Will is now a Harvard student. He says he learned a lot about his teenage brain from his mother.
Jensen's younger son Will is now a Harvard student. He says he learned a lot about his teenage brain from his mother.
A Partially Connected Frontal Lobe
Jensen thinks this explains what was going on inside the brain of her younger son, Will, when he turned 16. Like Andrew, he'd been a good student, a straight arrow, with good grades and high SAT scores. But one morning on the way to school, he turned left in front of an oncoming vehicle. He and the other driver were OK, but there was serious damage to the car.
"It was, uh, totaled," Will says. "Down and out. And it was about 10 minutes before morning assembly. So most of the school passed by my wrecked car with me standing next to it."
"And lo and behold," his mother adds, "who was the other driver? It was a 21-year-old — also probably not with a completely connected frontal lobe." Recent studies show that neural insulation isn't complete until the mid-20s.
This also may explain why teenagers often seem so maddeningly self-centered. "You think of them as these surly, rude, selfish people," Jensen says. "Well, actually, that's the developmental stage they're at. They aren't yet at that place where they're thinking about — or capable, necessarily, of thinking about the effects of their behavior on other people. That requires insight."
And insight requires — that's right — a fully connected frontal lobe.
Teen Brains Are Not Fully Connected
The brain's "white matter" enables nerve signals to flow freely between different parts of the brain. In teenagers, the part that governs judgment is the last to be fully connected.Source: Nature Neuroscience 2003
Credit: Elizabeth Sowell
More Vulnerable To Addiction
But that's not the only big difference in teenagers' brains. Nature made the brains of children and adolescents excitable. Their brain chemistry is tuned to be responsive to everything in their environment. After all, that's what makes kids learn so easily.
But this can work in ways that are not so good. Take alcohol, for example. Or nicotine, cannabis, cocaine, ecstasy ...
"Addiction has been shown to be essentially a form of 'learning,' " Jensen says. After all, if the brain is wired to form new connections in response to the environment, and potent psychoactive drugs suddenly enter that environment, those substances are "tapping into a much more robust habit-forming ability that adolescents have, compared to adults."
So studies have shown that a teenager who smokes pot will still show cognitive deficits days later. An adult who smokes the same dose will return to cognitive baseline much faster.
This bit of knowledge came in handy in Jensen's own household.
"Most parents, they'll say, 'Don't drink, don't do drugs,'" says Will, son number two. "And I'm the type of kid who'd say 'why?' "
When Will asked why, his mom could give him chapter and verse on drugs and teen brains. So they would know, she says, "that if I smoke pot tonight and I have an exam in two days' time, I'm going to do worse. It's a fact."
There were other advantages to having a neuroscientist mom, Will says. Like when he was tempted to pull an all-nighter.
"She would say, 'read it tonight and then go to sleep,'" he says. "And what she explained to me is that it will take [what you've been reading] from your short-term memory and while you sleep you will consolidate it. And actually you will know it better in the morning than right before you went to sleep."
It worked every time, he says.
It also worked for Andrew, the former Goth. He's now a senior at Wesleyan University, majoring in physics.
"I think she's great! I would not be where I am without her in my life!" Andrew says of his mom.
For any parent who has survived teenagers, there are no sweeter words.
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Willpower And The 'Slacker' Brain
by Robert Krulwich www.NPR.orgJanuary 26, 2010
This time, you say to yourself, this time I will do 50 chin-ups every day or skip dessert or call my mother every Friday. It's time to do those things that I know, I really, really know I should do.
And then you don't.
According to British psychologist Richard Wiseman, 88 percent of all resolutions end in failure. Those are his findings from a 2007 University of Hertfordshire study of more than 3,000 people.
How come so many attempts at willpower lose both their will and their power?
In our Radiolab excerpt on Morning Edition, with my co-host, Jad Abumrad, we propose an answer ...
Jonah Lehrer, one of our regular reporters (he writes all the time about the brain), told Jad and me about an experiment involving the prefrontal cortex, located just behind the forehead. It's the brain area largely responsible for willpower. This hunk of brain tissue, he says, has greatly expanded over the last few hundred-thousand years, but "it probably hasn't expanded enough." The reason our willpower is so often weak, he suggests, is because this bit of brain lacks a certain (how shall we put this?) ... muscularity.
The Experiment
In his book How We Decide, and in a recent Wall Street Journal article, Jonah writes about an experiment by Stanford University professor Baba Shiv, who collected several dozen undergraduates and divided them into two groups.
In the WSJ article, Jonah writes:
"One group was given a two-digit number to remember, while the second group was given a seven-digit number. Then they were told to walk down the hall, where they were presented with two different snack options: a slice of chocolate cake or a bowl of fruit salad."
And then he writes:
"Here's where the results get weird. The students with seven digits to remember were nearly twice as likely to choose the cake as students given two digits. The reason, according to Professor Shiv, is that those extra numbers took up valuable space in the brain — they were a "cognitive load" — making it that much harder to resist a decadent dessert. In other words, willpower is so weak, and the prefrontal cortex is so overtaxed, that all it takes is five extra bits of information before the brain starts to give in to temptation."
It turns out, Jonah explains, that the part of our brain that is most reasonable, rational and do-the-right-thing is easily toppled by the pull of raw sensual appetite, the lure of sweet. Knowing something is the right thing to do takes work — brain work — and our brains aren't always up to that. The experiment, after all, tells us brains can't even hold more than seven numbers at a time. Add five extra digits, and good sense tiptoes out of your head, and in comes the cake. "This helps explain why, after a long day at the office, we're more likely to indulge in a pint of ice cream, or eat one too many slices of leftover pizza," Lehrer writes.
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Teen Drinking May Cause Irreversible Brain Damage
by Michelle Trudeau www.NPR.orgJanuary 25, 2010
The red specks highlight where the integrity of the brain's white matter is significantly less in the teens who binge drink, compared to those who do not.
For teenagers, the effects of a drunken night out may linger long after the hangover wears off.
A recent study led by neuroscientist Susan Tapert of the University of California, San Diego compared the brain scans of teens who drink heavily with the scans of teens who don't.
Tapert's team found damaged nerve tissue in the brains of the teens who drank. The researchers believe this damage negatively affects attention span in boys, and girls' ability to comprehend and interpret visual information.
"First of all, the adolescent brain is still undergoing several maturational processes that render it more vulnerable to some of the effects of substances," Tapert says.
In other words, key areas of the brain are still under construction during the adolescent years, and are more sensitive to the toxic effects of drugs and alcohol.
Damage to the brain of a teenage drinker, top view
Thought, Memory Functions Affected
For the study, published last month in the journal Psychology of Addictive Behaviors, Tapert looked at 12- to 14-year-olds before they used any alcohol or drugs. Over time, some of the kids started to drink, a few rather heavily — consuming four or five drinks per occasion, two or three times a month — classic binge drinking behavior in teens.
Comparing the young people who drank heavily with those who remained non-drinkers, Tapert's team found that the binge drinkers did worse on thinking and memory tests. There was also a distinct gender difference.
"For girls who had been engaging in heavy drinking during adolescence, it looks like they're performing more poorly on tests of spatial functioning, which links to mathematics, engineering kinds of functions," Tapert says.
And the boys?
"For boys who engaged in binge drinking during adolescence, we see poor performance on tests of attention — so being able to focus on something that might be somewhat boring, for a sustained period of time," Tapert says. "The magnitude of the difference is 10 percent. I like to think of it as the difference between an A and a B."
Teenage Tendency To Experiment To Blame
Pediatrician and brain researcher Ron Dahl from the University of Pittsburgh notes that adolescents seem to have a higher tolerance for the negative immediate effects of binge drinking, such as feeling ill and nauseated.
"Which makes it easier to consume higher amounts and enjoy some of the positive aspects," Dahl says. "But, of course, that also creates a liability for the spiral of addiction and binge use of these substances."
He adds that there is a unique feature of the teenage brain that drives much behavior during adolescence: The teen brain is primed and ready for intense, all-consuming learning.
"Becoming passionate about a particular activity, a particular sport, passionate about literature or changing the world or a particular religion" is a normal, predictable part of being a teenager, he says.
"But those same tendencies to explore and try new things and try on new identities may also increase the likelihood of starting on negative pathways," he adds.
Damaged Brain Tissue
Tapert wanted to find out in what way binge drinking affects a teen's developing brain. So using brain imaging, she focused on the white matter, or nerve tissue, of the brain.
"White matter is very important for the relay of information between brain cells; and we know that it is continuing to develop during adolescence," Tapert says.
So Tapert imaged the brains of two groups of high school students: binge drinkers and a matched group of teens with no history of binge drinking. She reports in her recent study a marked difference in the white matter of the binge drinkers.
"They appeared to have a number of little dings throughout their brains' white matter, indicating poor quality," Tapert says.
And poor quality of the brain's white matter indicates poor, inefficient communication between brain cells.
"These results were actually surprising to me because the binge drinking kids hadn't, in fact, engaged in a great deal of binge drinking. They were drinking on average once or twice a month, but when they did drink, it was to a relatively high quantity of at least four or five drinks an occasion," she says.
In another study, Tapert reported abnormal functioning in the hippocampus — a key area for memory formation — in teen binge drinkers. Reflecting their abnormal brain scans, the teen drinkers did more poorly on learning verbal material than their non-drinking counterparts.
What remains unknown, says Tapert, is if the cognitive downward slide in teenage binge drinkers is reversible.
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Hardwired For Doom: Brain, Mind And Fate
January 25, 2010By Adam Frank www.NPR.org
"Get down from there!"
My 15-year-old son and I had just come out of the movie theater. After two hours of the usual explosions and mayhem (I can't really remember what movie we had seen) I made the mistake of telling him to wait outside while I chatted with a friend. Five minutes later I find him on the theater roof jumping from one large air conditioning unit to the other. "What are you crazy?" I yelled hoping to get him down, and us away, from there before the blue siren's arrived.
Well, yes. Of course he's crazy. He's 15. Ever since we made the mistake of watching District B13 my son has become a fan of Parkour, which is like freestyle skiing without skis or snow or mountains. Practitioners of Parkour (or its variant Free-running) believe that a good time equals climbing straight up the face of impossibly high walls or leaping from the roof of one 10 story building to another (even if there happens to be a city street in between them). It is a mix of gymnastics, rock climbing and insanity. It's beautiful, graceful and terrifying (if you are a parent). So of course my son loves it and yearns to be an adept. I am trying to guide him to something safer.
Which brings us to today's question. What is the balance between the hardwiring evolution has given us and the cultural programming we have given ourselves?
Brain researchers have found that thrill seeking like Parkour is, to some degree, programmed into the teenage brain. It's part of the need for intense learning. Eventually part of that learning will include internal dialogues like "Don't jump from that building. Its stupid and we will die." But until that kind maturation occurs teenagers need parents around to tell them "Don't jump from that building. Its stupid and you will die."
But we are more than just the hardwiring of our brains, aren't we? In many regards the brains we have now were set in place, genetically at least, some 50,000 years ago. But the difference in culturally constructed behavior between then (hunter-gathers living in small tribes) and now is so vast that we have clearly invented some powerful new behaviors. From the development of agriculture 9000 or so years ago to kingship based empires of the first few millennia BC to the crazy caffeine-fueled high-tech scramble we inhabit now, hasn't culture and not genetics driven our evolution?
This is a question of more than academic interest. One can imagine all kinds of genetically hardwired behavior that was really useful for small bands of social hominids a million years ago that present real problems for a now global species with nuclear weapons (among other toys). Evolutionary psychology combined with impressive advances in brain science is an exciting branch of research that lays bare the physical causes of some aspects of our behavior. But how much of that behavior is hardwired and how much lies in the "new" evolutionary domains of culture (created via the imagination)?
There is the world we are born into and the one we create. What are the boundaries between them and how much play do we have in pushing those boundaries around?
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